LIghting is a VERy difficult thing to get right, people say it all the time so keeping lightmap res low till ship is a good idea. I have the flicking in areas and its where there is a long thin ‘light’ that shine on areas of terrain, tho atm I don’t know how to stop it just yet,prob. clashing lights, settings here or there…light is just a PITA everybody knows it, depending of course on what kind of scene you have etc. True especially with large worlds.
For now preston just disable ray tracing in project settings and it will force a restart and you’ll likely be fine. Sounds like, as many of us, join the crowd, you’re prob running out of ram ? Increasing lightmap resolution is another good way to crash depending on scene complexity.